Method and apparatus for making bags



March 20, 1934.

T. E. co'rY 1,95l,471 I IN GS March 20, 1934. T, E CQTY l,95l,471

METHOD AND APPARATUS FOR MAKING BAGs Filed Jan. 29, 1932 4 Sheets-Sheet 2 ATTORNEY March 20, 1934. T. E. coTY METHOD AND APPARATUS FOR MAKING BAGS Filed Jan. 29. 1932 4 sneets-sneet 43 g INV ro BY fi ATTORNEY March 20, 1934. T, E CQTY 1,951,47l

METHOD AND APPARATUS Eon MAKlNG BAGs Filed Jan. 29, 1932 4 sheetsfsheet 4 lNI/ENTOR. BY fiwd tW ATTORNEY.

Patented Mar. 20, 1934 UNITED sTATEs PATENT oFFlcF.

METHOD AND APPARATUS FOR MAKING BAGS 7 Claims.

My present invention relates to methods and apparatus for making bags having particular application to the production of paper bags, especially such as are used for heavy pulverulent materials, suchas cement or the like.

In these bags it is important that the bottoms be capable of sustaining shock without cracking apart at the seams. In order to attain this I have devised a bag having a narrow bottom in which the front and back folds overlap at the corners as hereinafter more particularly described, and in which the lip or tab which is formed by the tongue cutter, and which it is important to have on the bag because that facilitates its manufacture in ways well understood, after its utility has ceased, is cut off entirely. One reason for making the bottoms of the bags wide has been the necessity of providing space upon the first fold between the creases for this tab or lip. The method of operation is to cut the tongue, to initiate the fold, and then after the fold has been started, to cut off the tongue and complete the fold. The arrangement will be made more clear by the drawing,-presently to be more particularly described.

I have also devised a new and useful apparatus for affecting this change in construction, In this there are three knives', one to form the thumb-notch or tongue in the usual way; a second one to cut off the bag blank from the tube, and a third one for cutting off the lip or tab formed by the thumb-knife. These several knives are controlled in their course so as to work in a desired sequence, preferably by cams and camrollers, such as are shown in this case.

Repeated tests upon many bags of the character herein pointed out show that bags made in the old way with a wide bottom would give way under shocks at the end of the slits, and thisl might occur at any one of the four points shown by these cuts in the bag bottom. Making the thumb-notch on both ends of the bags did not remedy the trouble, and greatly complicated matters-because the notch would be on the wrong side of the tube on one end.

The apparatus which I have devised embraces a knife forcutting the thumb-notch; a cut-off knife for cutting blanks, from which bags are to be made; and a third knife for cutting off the tab left by the thumb-notch knife, with means for Operating these knives in proper sequence.

The accompanying drawing shows two aspects of my invention. In these Figure 1 shows a bag of the old form having a wide bottom;

Figure 2 shows the first step taken in devisin! the new form of bag;

Figure 3 is a side elevation partly in section, of apparatus for carrying out this step of cutting off the thumb-tab.

Figures 4 and 5 show the bag in different stages of manufacture;

Figure 6 shows the means tab in a different position; I

Figure 7 is a side elevation, partly in section; 05 of the apparatus for cutting off the tab;

Figure 8 is a plan of some of the parts shownin Figure 7; and I "2 Figure 9 is a view on a smaller scale of a completed bag.

Figure 10 is a diagrammatic side elevation of a complete apparatus desirable to carry out the process herein outlined.

Figure 1 shows the bag of the old form. The weakness in its broad bottom is mostly at the points marked B, B. It will be seen that thefolds at the top and bottom do not overlap in such a fo'r cutting on the,

vway as to relnforce one another at this point.

Figure 2 shows the second step in endeavoring 1 to correct this difilculty. In this, as shown at 80 D, the corners overlap each other, but the rectangle formed by the overlap on each end of the bottom is large and only a little additional strength is Secured, although in this case it is possible to cut off the tongue. In both of these 35 figures, A is the tube from which the bag is formed, C is the rear or second flap, and Cl is the lip or thumb-tab. Figure 4 is a view of the bag with the folds initiated, but before the creases are made. It is at this stage of the manufacture that the tongue Cl is cut off and that operation is shown in Figure 5, where the bag shown in Figure 4 is turned over so as to show the unbroken side of the tube.

Figure 9 is a view of the completed bag, and it will be observed that the overlap at E and D is sufllcient to relnforce the bottom very strongly.

Turningy now to the mechanlcal parts of the invention, B should be read in connection with the Patent No. 1310972, issues to Aured c. cow. 1 and myself, and particularly in connection with the parts shown in Figure 3 of that patent. I have to some extent used the same reference characters so as to connect this case with that, for convenience of examination, and have removed from the drawing for cleamess thevstop mechanism shown in the patent in vFigure 3. Therefore, F is the cylinder which carries the bag forward to be opened by means of the pins thereon, these being shown dotted in Figure 3 no of this case, and being a common instrument in paper-bag machines. The arm F* is used as shown in that patent, and as indicated here in dotted lines, to take the upper sheet of the bag from the pins and hold its mouth open, while the opening cylinder G carries it forward. It will be observed that the hook G4 shown in dotted lines takes the bag from the guide G3 shown in the upper right-hand part of the figure as it progresses between the cylinders F and G and carries it down upon the finger Ffl, which moves down With the bag sufliciently to hold the latter open until the cylinder G and the cut-off cylinder H, which is substituted for the "coacher cylinder H in the patent, engage the bag and I carry it forward in conjunction With the belts i lip Cl,

' tab.

lto

or tapes H10.

I have not deemed it necessary to describe the other parts of the cylinder F, because the operation is fully pointed out in the Letters-Patent referred to.

The cylinder G is provided with 'fixed cams G1, G2, and the finger G4 already referred to, which is operated by cam-roller G5; the adjustment g permitsL moving these cams relative to one another so as to control the action of the cam-roller G5.

The cut-off cylinder H is provided with a fixed cam H1, the position of which may be adjusted by means of the slot and bolt h, as is well understood. This cam H1 controls a cam-roller H3 upon an arm H2 held by a spring to a member H8, so as to keep the cam-roller in engagement with the stationary cam as it rotates around it. The arm is pivoted at HAi and carries arms H5; with a pin and slot connection which operates the tubes H6 (see also Figure 7). These pins Hll are contained in the tubes and pierce the the cam being timed to withdrawthe tubes, allowing the pins to project when this lip is brought into the position above them. The further rotation of the cylinder H brings the parts around to the position shown in Figure 6, and here the tab or lip is pushed off by the tubes and falls into any convenient receptacle.

I have not deemed it necessary to describe the action of the cut-off knife G10, because that is like the one shown and described in the Letters- Patent above referred to.

In Figure 10 I have shown in diagrammatic form the steps of the process' described, and indicated the apparatus necessary to carry out that process. In general, .the form of the bottoming device is the same as that shownin the Patent No. 1.770.972, already referred to, with such modification as is necessary for cutting off the thumb- The figure also shows in plan in the sketches 1 to 5 the appearance of the bag at the various steps of the formation, Figure 1 being as it comes from the tuber; Figure 2 after the thumb-tab C1 is formed and the slits for the bottoming operation made; Figure 3, with the flap opened at the end of the tube; Figure 4 with one flap folded over, and Figure 5 the completed bag.

O is the roll from which the web A is drawn over the feed rollers,- which are not lettered as they are commonly understood in apparatus of this kind. At N is shown the thumb-knife and at S is the paste apparatus for the longitudinal seam. At P I have shown the slitters; Q, 'the feed rollers with the usual snatch roll. At F is the opening device for the bottom of the bag with the roll G, shown more fully in Fig. 3 in this case. H is the cutting device for removing the tab; J shows feed rollers; I, I, show the pasteapplying mechanism for the bottomer. The rolls carrying the notches k, k, co-opera-te with the creasers K, Kl, as the bag is carried upy facture and the improvement resultingl therefrom.

What is claimed isz- 1. In a paper-bag machine, the combination of a thumb-knife, a cut-off knife and av thumb-tabknife for cutting off the tab at desired times,

with means for actuating the knives in proper sequence.

2. In a paper-bag machine, the combination of a knife for cutting a thumb-notch; a cut-off knife for cutting blanks from which bags are to be made; a knife for cutting off the tab left by the thumb-knife; and cams and cam rollers for actuating the knives at desired times.

3. The improvement in the art of making paper bags, which consists in cutting a thumb-tab in one side of the tube; cutting oif a blank from the tube at the base of the tab; initiating the fold at the bottom; cutting off the tab; and completing the fold and sealing the bottom.

4. As an improvement in the art of makingl paper bags, the step of cutting olf the thumbtab at the time the blank is opened to form the bottom and priorto the folding and sealing thereof.

5. In a paper bag machine, means for initiating the fold of the bottom, means for cutting off the thumb-tab from the blank, and means for completing the fold and sealing the bottom.

6. In a paper-bag machine, means for cutting off the\tab from the bottom of a blank; pins for holding the tabs cut off, the pins mounted in tubes; and means for moving the tubes to remove the tabs from the pins.

7. In the combination of claim 6, cams and cam-rollers for moving -the tubes at desired times.

' THOMAS EARL COTY. 

